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| IBS |
Even though signs and symptoms are uncomfortable, IBS — unlike ulcerative colitis and Crohn's disease, which are forms of inflammatory bowel disease — doesn't cause changes in bowel tissue or increase your risk of colorectal cancer.Only a small number of people with irritable bowel syndrome have severe signs and symptoms. Some people can control their symptoms by managing diet, lifestyle and stress. Others will need medication and counseling.
SYMPTOMS
The signs and symptoms of irritable bowel syndrome can vary widely from person to person and often resemble those of other diseases. Among the most common are:
Abdominal pain or crampingA bloated feelingGas Diarrhea or constipation — sometimes alternating bouts of constipation and diarrheaMucus in the stool
For most people, IBS is a chronic condition, although there will likely be times when the signs and symptoms are worse and times when they improve or even disappear completely.
Symptoms that may indicate a more serious condition include:
Rectal bleeding,Abdominal pain that progresses or occurs at night,Weight loss
Your doctor may be able to help you find ways to relieve symptoms as well as rule out colon conditions, such as inflammatory bowel disease and colon cancer. Your doctor can also help you avoid possible complications from problems such as chronic diarrhea.
CAUSES
It's not known exactly what causes irritable bowel syndrome, but a variety of factors play a role. The walls of the intestines are lined with layers of muscle that contract and relax in a coordinated rhythm as they move food from your stomach through your intestinal tract to your rectum. If you have irritable bowel syndrome, the contractions may be stronger and last longer than normal, causing gas, bloating and diarrhea. Or the opposite may occur, with weak intestinal contractions slowing food passage and leading to hard, dry stools.
Abnormalities in your gastrointestinal nervous system also may play a role, causing you to experience greater than normal discomfort when your abdomen stretches from gas or stool. Poorly coordinated signals between the brain and the intestines can make your body overreact to the changes that normally occur in the digestive process. This overreaction can cause pain, diarrhea or constipation.
Triggers vary from person to person
Stimuli that don't bother other people can trigger symptoms in people with IBS — but not all people with the condition react to the same stimuli. Common triggers include:
Foods. The role of food allergy or intolerance in irritable bowel syndrome is not yet clearly understood, but many people have more severe symptoms when they eat certain things. A wide range of foods has been implicated — chocolate, spices, fats, fruits, beans, cabbage, cauliflower, broccoli, milk, carbonated beverages and alcohol to name a few.Stress. Most people with IBS find that their signs and symptoms are worse or more frequent during periods of increased stress, such as finals week or the first weeks on a new job. But while stress may aggravate symptoms, it doesn't cause them.Hormones. Because women are twice as likely to have IBS, researchers believe that hormonal changes play a role in this condition. Many women find that signs and symptoms are worse during or around their menstrual periods.Other illnesses. Sometimes another illness, such as an acute episode of infectious diarrhea (gastroenteritis) or too many bacteria in the intestines (bacterial overgrowth), can trigger IBS.
COMPLICATIONS
Diarrhea and constipation, both signs of irritable bowel syndrome, can aggravate hemorrhoids. In addition, if you avoid certain foods, you may not get enough of the nutrients you need, leading to malnourishment.
But the condition's impact on your overall quality of life may be the most significant complication. These effects of IBS may cause you to feel you're not living life to the fullest, leading to discouragement or depression.
DIAGNOSIS
A diagnosis of irritable bowel syndrome depends largely on a complete medical history and physical exam.
Criteria for making a diagnosis
Because there are usually no physical signs to definitively diagnose IBS, diagnosis is often a process of ruling out other conditions. To help this process, researchers have developed two sets of diagnostic criteria for IBS and other functional gastrointestinal disorders — conditions in which the bowel appears normal but doesn't work (function) normally. Both criteria are based on symptoms after other conditions have been ruled out.
Rome criteria. According to these criteria, you must have certain signs and symptoms before a doctor diagnoses irritable bowel syndrome. The most important are abdominal pain and discomfort lasting at least three days a month in the last three months, associated with two or more of following: improvement with defecation, altered frequency of stool or altered consistency of stool.Manning criteria. These criteria focus on pain relieved by defecation, having incomplete bowel movements, mucus in the stool and changes in stool consistency. The more symptoms present, the greater the likelihood of IBS.
Your doctor will likely assess how you fit these criteria, as well as whether you have any other signs or symptoms that might suggest another, more serious, condition. Some red flag signs and symptoms that suggest a need for additional testing include:
New onset after age 50Weight lossRectal bleedingFeverNausea or recurrent vomitingAbdominal pain, especially if it's not completely relieved by a bowel movement, or occurs at nightDiarrhea that is persistent or awakens you from sleepAnemia related to low iron
If you fit the IBS criteria and don't have any red flag signs or symptoms, your doctor may suggest a course of treatment without doing additional testing. But if you don't respond to that treatment, you'll likely require more tests.
Additional tests
Your doctor may recommend several tests, including stool studies to check for infection or problems with your intestine's ability to take in the nutrients from food (malabsorption). You may undergo a number of tests to rule out other causes for your symptoms.
Imaging tests:
Flexible sigmoidoscopy. This test examines the lower part of the colon (sigmoid) with a flexible, lighted tube (sigmoidoscope).Colonoscopy. In some cases, especially if you are age 50 or older or have other signs of a potentially more serious condition, your doctor may perform this diagnostic test in which a small, flexible tube is used to examine the entire length of the colon.X-ray (radiography). Sometimes doctors will use X-rays to obtain an image of your colon.Computerized tomography (CT) scan. CT scans produce cross-sectional X-ray images of internal organs. CT scans of your abdomen and pelvis may help your doctor rule out other causes of your symptoms, especially if you have abdominal pain.Lower GI series. In this test, doctors fill your large intestine with a liquid (barium) to make it easier to see any problems on the X-ray.
Laboratory tests:
Lactose intolerance tests. Lactase is an enzyme you need to digest the sugar found in dairy products. If you don't produce this enzyme, you may have problems similar to those caused by irritable bowel syndrome, including abdominal pain, gas and diarrhea. To find out if this is the cause of your symptoms, your doctor may order a breath test or ask you to remove milk and milk products from your diet for several weeks.Breath tests. Your doctor may perform a breath test to look for a condition called bacterial overgrowth, in which bacteria from the colon grow up into the small intestine, leading to bloating, abdominal discomfort and diarrhea. This is more common among people who have had bowel surgery or who have diabetes or some other disease that slows down digestion.Blood tests. Celiac disease is sensitivity to wheat, barley and rye protein that may cause signs and symptoms like those of irritable bowel syndrome. Blood tests can help rule out this disorder. Children with IBS have a far greater risk of celiac disease than do children who don't have IBS. If your doctor suspects that you have celiac disease, he or she may perform an upper endoscopy to obtain a biopsy of your small intestine.Stool tests. If you have chronic diarrhea, doctors may want to examine your stool for bacteria or parasites.
TREATMENT
Because it's not clear what causes irritable bowel syndrome, treatment focuses on the relief of symptoms so that you can live as normally as possible.
In most cases, you can successfully control mild signs and symptoms of irritable bowel syndrome by learning to manage stress and making changes in your diet and lifestyle. Try to avoid foods that trigger your symptoms. Also try to get enough exercise, drink plenty of fluids and get enough sleep.
If your problems are moderate or severe, you may need more than lifestyle changes. Your doctor may suggest and medications.
Dietary changes:
Eliminating high-gas foods. If you have bothersome bloating or are passing considerable amounts of gas, your doctor may suggest that you cut out such items as carbonated beverages, vegetables — especially cabbage, broccoli and cauliflower — and raw fruits.Eliminating gluten. Research shows that some people with IBS report improvement in diarrhea symptoms if they stop eating gluten (wheat, barley and rye). This recommendation remains controversial, and the evidence is not clear.Eliminating FODMAPs. Some people are sensitive to types of carbohydrates such as fructose, fructans, lactose and others, called FODMAPs (fermentable oligo-, di-, and monosaccharides and polyols). FODMAPs are found in certain grains, vegetables, fruits and dairy products. However, often people are not bothered by every FODMAP food. You may be able to get relief from your IBS symptoms on a strict low FODMAP diet and then reintroduce foods one at time.
Medications:
Fiber supplements. Taking fiber supplements, such as psyllium (Metamucil) or methylcellulose (Citrucel), with fluids may help control constipation. Fiber obtained from food may cause much more bloating compared with a fiber supplement. If fiber doesn't help symptoms, your doctor may prescribe an osmotic laxative such as milk of magnesia or polyethylene glycol.Anti-diarrheal medications. Over-the-counter medications, such as loperamide (Imodium), can help control diarrhea. Some people will benefit from medications called bile acid binders, such as cholestyramine (Prevalite), colestipol (Colestid) or colesevelam (Welchol), but these can lead to bloating.Anticholinergic and antispasmodic medications. These medications, such as hyoscyamine (Levsin) and dicyclomine (Bentyl), can help relieve painful bowel spasms. They are sometimes used for people who have bouts of diarrhea, but they can worsen constipation and can lead to other symptoms, such as difficulty urinating. They should also be used with caution among people with glaucoma.
Antidepressant medications. If your symptoms include pain or depression, your doctor may recommend a tricyclic antidepressant or a selective serotonin reuptake inhibitor (SSRI). These medications help relieve depression as well as inhibit the activity of neurons that control the intestines.
If you have diarrhea and abdominal pain without depression, your doctor may suggest a lower than normal dose of tricyclic antidepressants, such as imipramine (Tofranil) or nortriptyline (Pamelor). Side effects of these drugs include drowsiness and constipation. SSRIs, such as fluoxetine (Prozac, Sarafem) or paroxetine (Paxil), may be helpful if you're depressed and have pain and constipation.
Antibiotics. Some people whose symptoms are due to an overgrowth of bacteria in their intestines may benefit from antibiotic treatment. Some people with symptoms of diarrhea have benefited from rifaximin (Xifaxan), but more research is needed.Counseling. You may benefit from counseling if you have depression or if stress tends to worsen your symptoms.
Medication specifically for IBS
Two medications are currently approved for specific cases of IBS:
Alosetron (Lotronex). Alosetron is designed to relax the colon and slow the movement of waste through the lower bowel. The Food and Drug Administration (FDA) removed it from the market for a time, but has since allowed alosetron to be sold again.
However, alosetron can be prescribed only by doctors enrolled in a special program and is intended for severe cases of diarrhea-predominant IBS in women who haven't responded to other treatments. Alosetron is not approved for use by men. It has been linked to rare but important side effects, so it should only be considered when other treatments are not successful.
Lubiprostone (Amitiza). Lubiprostone works by increasing fluid secretion in your small intestine to help with the passage of stool. It is approved for women age 18 and older who have IBS with constipation. Its effectiveness in men is not proved, nor its long-term safety. Common side effects include nausea, diarrhea and abdominal pain. Lubiprostone is generally prescribed only for women with IBS and severe constipation for whom other treatments haven't been successful.
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